The present invention relates to receptacles for objects, and more particularly to film cassettes. Still more particularly, the invention relates to a cassette for an X-ray film.
In the past, it has often been found to be disadvantageous, especially in connection with X-ray cassettes, when the user was unable to ascertain whether or not the cassette was charged with the film, without opening the cassette. As a result of this inability, mistakes have often been made in that either an empty cassette was used during an X-ray exposure or, especially in automatic feeding and discharging systems, a single cassette was used more than once. In each instance, the intended picture had to be taken again, which is not only very wasteful of time, but also exposes the patient to unnecessary amount of radiation.
To avoid this disadvantage, it was proposed in the German Pat. No. 825 947 to provide the X-ray cassette, which includes two cassette halves that together bound a space from which ambient light is excluded, with a movable element which assumes a first perceptible position when the cassette is charged, and a second perceptible position when the cassette is not charged.
However, such an arrangement can only be used in connection with rigid plates. An X-ray film, because of its flexibility and its relative thickness, would not be indicated by such an arrangement.